1. Field of the Invention
This invention relates to a control device for automatic transmissions with an overdrive mechanism in automobiles and more particularly to a control device for automatic transmissions which reduces shocks produced when the manual lever is shifted from the natural (N) to the drive (D) or the reverse (R) positions.
2. Description of the Prior Art
Generally in automatic transmissions, when the manual lever is manually shifted from the N (neutral)-position to the D (drive)-position, an abrupt engagement of friction elements produces shocks. To prevent the shock in manual-shifting, there has been proposed a control device for automatic transmissions by which when the manual lever is shifted from the N-position to the D-position, the planetary gear set is momentarily shifted to the 2nd or 3rd gear. However, in the conventional automatic transmission, the overdrive mechanism has not been utilized to prevent the said manual shift shocks.